Malicious PDF — malware analysis report

Static analysis result for SHA-256 bffc61655f4120fc…

MALICIOUS

PDF

93.5 KB Created: 2021-09-02 22:21:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 3ef98bc812c8cde11b53f40d97a8b87c SHA-1: 0897eb789002e1c1f64468a663a63bdc0a656725 SHA-256: bffc61655f4120fca0636d5c43848e1fd69f02e45303357ccd19fee412ad185c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. Although no scripts were directly extracted, the structure and URL patterns are consistent with a malicious PDF designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://zuche0551.com/upload/file/6736841679.pdf In PDF document text
    • http://nakakinpump.kr/fckeditor/upload/file/36374198965.pdfIn PDF document text
    • http://weighlessthisyear.com/ckfinder/userfiles/files/xalixuxofavebalo.pdfIn PDF document text
    • http://tikatalog.sk/_files/file/88519200270.pdfIn PDF document text
    • https://frpeteradeyemi.com/userfiles/files/93055093726.pdfIn PDF document text
    • http://the100voicesofgospel.de/fichiers/newsletter/file/xefokuwunanafelofabe.pdfIn PDF document text
    • https://avistravel.ro/userfiles/file/nesuvatuwarepi.pdfIn PDF document text
    • http://asbufestival.com/uploads/FCK_files/file/14017272210.pdfIn PDF document text
    • https://oykufestivali.com/ckfinder/userfiles/files/ruzesasoburoginonobi.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607854b73e9f6---75147440314.pdfIn PDF document text
    • http://bvmnotarissen.nl/app/webroot/files/ckeditor_files/files/91511487905.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16078ed0fe9eb9---giguvarojizumika.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/ba3d497e8f0e385579e45e539d0cd919/63509363830.pdfIn PDF document text
    • http://toshiba-center.ru/uploads/files/vapusotesinubudemax.pdfIn PDF document text
    • https://wonkingchina.com/d/files/3333689646.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160710297c7c8c---58433768888.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/1copn138vjugbkf570r5dhhv1d/84559358481.pdfIn PDF document text
    • https://securitegenerale.tn/userfiles/file/doporezuzuganotoz.pdfIn PDF document text
    • http://allamericannursing.com/userfiles/file/13771670608.pdfIn PDF document text
    • http://kirakuramen.com/uploads/files/kulotipuj.pdfIn PDF document text
    • http://bafiti.com/sklep/userfiles/file/puwewovigi.pdfIn PDF document text
    • http://xn--80aatg4aaaddkhfhbf3evf.xn--p1ai/ckfinder/userfiles/files/mokugov.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=2004+hyundai+tiburon+manual+transmissionPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010798.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10798 10956 bytes
SHA-256: f42248f798a0171a1f937db2ea4e6ecdd513626c87dfce434d4309c29d7ee558
font_01_sfnt_off000120d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120D8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000138ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x138EA 18116 bytes
SHA-256: f23cc6b92e218e87f353020dfdcd877e7ec22c28fdbe466bf19a502529da3bd3